Objective:
Prepare clean variables for injury outcome and road user classification.
- Standardize person_type categories
- Remove or label unspecified in person_injury
- Create binary variable: fatality (1 = killed, 0 = otherwise)
- Create binary variable: injured (1 = injured, 0 = otherwise)
- Display frequency table of injury outcomes by road user type
Objective:
Prepare clean variables for injury outcome and road user classification.